Yes but people can be moved about. Plus the costs of keeping open the civilian side of things can out way the cost of keeping just a few personnel. As for hangar size, yes there are proposals to build a hangar for C17 work but to allow civil onto a USAF airbase would just not be practical to the USAF Yes ATA tristars etc do some movements for them but its not that simple.
The question is will the USAF still be at Mildenhall when the time comes for Marshalls to move. :rolleyes: